Season two's premiere will see Holmes called to London to revisit an old case, while Watson (Lucy Liu) delves into her partner's past in England.

"We couldn't be more excited to have this opportunity to see Sherlock's old stomping grounds," said Elementary creator Robert Doherty.

"By meeting old friends and revisiting prior cases, Watson will gain even more insight into Holmes. She'll have to keep up with a Sherlock who is both more comfortable in his surroundings and even bolder in testing the limits of those around him."